FALC
56
PEF 2256 H/E
E1 Registers
User’s Manual
Hardware Description
242
DS1.1, 2003-10-23
Framer Mode Register 2 (Read/Write)
Value after reset: 00
H
RFS(1:0)
Receive Framing Select
00 = Doubleframe format
01 = Doubleframe format
10 = CRC4 Multiframe format
11 = CRC4 Multiframe format with modified CRC4 Multiframe
alignment algorithm (Interworking according to ITU-T G.706
Annex B). Setting of FMR3.EXTIW changes the reaction after
the 400-ms time-out.
RTM
Receive Transparent Mode
Setting this bit disconnects control of the internal elastic store from the
receiver. The elastic store is now in a “free running” mode without any
possibility to actualize the time slot assignment to a new frame
position in case of resynchronization of the receiver. This function can
be used together with the “disable AIS to system interface” feature
(FMR2.DAIS) to realize undisturbed transparent reception.
This bit should be enabled in case of unframed data reception mode.
DAIS
Disable AIS to System Interface
0 =
AIS is automatically inserted into the data stream to RDO if
FALC
56 is in asynchronous state.
1 =
Automatic AIS insertion is disabled. Furthermore, AIS insertion
can be initiated by programming bit FMR2.SAIS.
SAIS
Send AIS Towards System Interface
Sends AIS on output RDO towards system interface. This function is
not influenced by bit FMR2.DAIS.
PLB
Payload Loop-Back
0 =
Normal operation. Payload loop is disabled.
1 =
The payload loop-back loops the data stream from the receiver
section back to transmitter section. Looped data is output on
pin RDO. Data received on port XDI, XSIG, SYPX and XMFS is
ignored. With XSP.TT0 = 1 time slot 0 is also looped back. If
XSP.TT0 = 0 time slot 0 is generated internally. AIS is sent
7
0
FMR2
RFS1
RFS0
RTM
DAIS
SAIS
PLB
AXRA
ALMF
(1E)